This Gothic-Renaissance house on Masarykovo náměstí takes its name from fish pond builder Josef Štěpánek Netolický, who acquired it by marriage in 1522. After a major reconstruction in 2014-2016, it now houses the Třeboň Fish Pond Heritage Centre with a permanent interactive exhibition on the region's pond-building history and the Golden Canal. The building retains Renaissance wall paintings of the seven liberal arts and a Gothic cellar; the courtyard holds a working model of the pond system. Lectures, workshops and temporary exhibitions take place here regularly.